Radical psychiatrists and others assert that mental illness is a myth. The opening and closing portions of the paper deal with the impact such argument has had in law and psychiatry. The body of the paper discusses the five versions of the myth argument prevalent in radical psychiatry: (A) that there is no such thing as mental illness; (B) that those called ?mentally ill? are really as rational as everyone else, only with different aims; that the only reasons anyone ever thought differently was (C) because of unsophisticated category mistakes or (D) because of an adherence to the epistemology of a sick society; and (E) that the phrase ?mental illness? is used to mask value judgments about others? behavior in pseudo?scientific respectability. Reasons are given for rejecting each of these versions of the argument that mental illness is a myth